Ali ibn Abi Talib

Ali ibn Abi Talib (20 September 601-27 January 661) was the Caliph of the Rashidun Caliphate from 656 to 661, succeeding Uthman ibn Affan and  and preceding Hasan ibn Ali. He was the cousin and son-in-law of the prophet Muhammad, and the final of the "rightly-guided caliphs". He was killed in 661 after losing the First Fitna to rebels led by Aisha, the young widow of Muhammad.

Biography
Ali ibn Abi Talib was born on 20 September 601 in the Ka'aba of Mecca in present-day Saudi Arabia to Abu Talib, the Custodian of the Ka'aba and a Sheikh of the powerful Banu Hashim branch of the powerful Quraysh tribe. In 610 AD, a ten-year-old Ali professed to Islam, the first male to embrace the religion. He became a follower of the prophet Muhammad, and aside from the Battle of Tabuk, he fought in all of the battles of the campaigns of Muhammad to spread Islam. In 624 AD he killed Walid ibn Utbah at the Battle of Badr and used the bifurcated sword Zulfikar in battle. In 629 AD he defeated the Jews of Khaybar Oasis at the Battle of Khaybar, personally slaying Khaybar commander Marhab ibn Abu Zaynad.

After the death of Muhammad, Ali served his three successors. Uthman ibn Affan's assassination on 17 June 656 led to Ali being proclaimed the new Caliph of the Rashidun Caliphate by Muhammad's followers, but his inability to deliver justice to Uthman's killers led to Aisha leading a rebellion. On 7 November 656, Ali's Rashidun army defeated Aisha at the Battle of the Camel. However, in 661 Ali was attacked in the Grand Masjid of Kufa in Iraq while praying, and he was stabbed to death with a poisoned sword. Shortly after his death, his successor Hassan ibn Ali abdicated, letting Muawiyah ibn Abi Sufyan establish the Umayyad Caliphate.